Method and device for hydrogen and hydrocarbon sensing

Abstract

One embodiment of a method of fabricating a sensor element for an exhaust gas sensing device, comprises disposing an electrolyte in ionic communication with a sensing electrode and a reference electrode to form the sensor element. The sensing electrode comprises an activator comprising silica and an oxide of an element. The element is selected from the group consisting of alkaline earth elements, rare earth elements, and combinations comprising at least one of the foregoing elements.

We claim:  
     
       1. A method of fabricating a sensor element for an exhaust gas sensing device, said sensor comprising a sensing electrode and a reference electrode in ionic communication with an electrolyte, said method comprising: 
       disposing a sensing electrode ink in ionic communication with the electrolyte, wherein the sensing electrode ink comprises an activator comprising silica and an oxide of an element and the element is selected from the group consisting of alkaline earth elements, rare earth elements, and combinations comprising at least one of the foregoing elements, and wherein the activator is not incorporated into the reference electrode, and  
       wherein the sensing electrode ink comprises about 0.5 wt % to about 5 wt % of the activator, based upon a total solid content of the ink, and  
       wherein the activator is composed of about 10 wt % to about 40 wt % of the silica and about 60 wt % to about 90 wt % of the element oxide, based upon the total weight of the activator.  
     
     
       2. The method of  claim 1 , wherein the element is selected from the group consisting of Ba, Sr, Ca, Hf, Zr, Bi, Sc, Y, La, Gd, Yb, and combinations comprising at least one of the foregoing elements. 
     
     
       3. The method of  claim 1 , wherein the reference electrode and the sensing electrode are disposed on a first side of the electrolyte. 
     
     
       4. The method of  claim 1 , further comprising disposing a protective layer on a side of the sensing electrode opposite the electrolyte, and heating the sensor element to a temperature of about 1,400° C. to about 1,550° C. 
     
     
       5. The method of  claim 1 , wherein the sensing electrode further comprises a platinum-gold alloy. 
     
     
       6. A sensor element, comprising: 
       an electrolyte in ionic communication with a sensing electrode and a reference electrode, wherein the sensing electrode comprises an activator comprising silica and an oxide of an element wherein the element is selected from the group consisting of alkaline earth elements, rare earth elements, and combinations comprising at least one of the foregoing elements, and wherein the activator is not incorporated into the reference electrode  
       wherein the sensing electrode comprises about 0.5 wt % to about 5 wt % of the activator, based upon the total weight of the sensing electrode, and wherein the activator comprises about 10 wt % to about 40 wt % of the silica and about 60 wt % to about 90 wt % of the element oxide, based upon the total weight of the activator.  
     
     
       7. The sensor element of  claim 6 , wherein the reference electrode and the sensing electrode are disposed on a first side of the electrolyte. 
     
     
       8. The sensor element of  claim 6 , wherein the electrolyte is porous. 
     
     
       9. A sensor element, comprising: 
       an electrolyte in ionic communication with a sensing electrode and a reference electrode, wherein the sensing electrode comprises an activator comprising silica and an oxide of an element wherein the element is selected from the group consisting of alkaline earth elements, rare earth elements, and combinations comprising at least one of the foregoing elements, and wherein the activator is not incorporated into the reference electrode, wherein the sensing electrode comprises about 0.5 wt % to about 5 wt % of the activator, based upon the total weight of the sensing electrode, and wherein the activator comprises about 10 wt % to about 40 wt % of the silica and about 60 wt % to about 90 wt % of the element oxide, based upon the total weight of the activator;  
       a protective layer disposed on a side of the sensing electrode opposite the electrolyte; and  
       a heater element in thermal communication with the sensing electrode, wherein the heater element is disposed on a side of the electrolyte opposite the sensing electrode.